The present invention relates to coalescing agents for paints, coatings, adhesives, and the like that can be used in a myriad of applications including, but not limited to, carpet backing, industrial coatings, architectural coatings, exterior insulating finishing systems, traffic paint, roof coatings, craft paints, paper coatings, and fiber coatings.
Coating compositions are used for a variety of applications, typically for the decoration or protection of surfaces. The coating compositions contain binders, typically emulsion polymers (e.g., latex), maintained in liquid solvents. Upon application of the coating materials, the solvents evaporate and the binders harden into a mechanically rigid state while binding pigments, fillers, and other additives.
Due to environmental concerns, among other things, there has been a movement toward reducing the amount of volatile organic compounds (VOCs) in paints, stains, and other coating compositions. However, some of the desirable properties of the coating compositions, like durability, opaqueness, and speed of drying, have been negatively affected by the absence of VOCs in those compositions. Companies have recently been searching for formulations and methods of making coating compositions with a low VOC content to meet new and developing regulations, while maintaining good physical properties in the final product.
The primary source of VOCs in paints is the coalescing agents. A coalescing agent functions as a solvent as well as a plasticizer for the polymer particles and assists in formation of a coherent film from the dispersed polymer phase in a typical waterborne formulation after the formulation is applied to a surface and allowed to dry. A desirable coalescing agent will allow formation of a film quickly and at a broad range of application temperatures for many different types of polymeric binder systems, meet the regulatory standards for VOC emissions, and allow the coating film to develop useful physical properties soon after application.
Because governments have established regulations setting forth guidelines relating to the amount of VOCs that may be released into the atmosphere, a need for low VOC coalescing agents that can be used in coating compositions such that desirable properties, like stability, compatibility, and film formation ability, are not compromised in the applied coating. Additionally, coalescing agents with these characteristics that are produced from renewable sources like grain and corn would be further advantageous as society reduces consumption of petroleum.